Reciprocating pump or motor



Jan. 11, 1949. J, c, NAYLQR 2,458,869

VRECIPROCATING PUMP ORYMOTOR Filed Jan. 4, 1945 4 z sheets-sheet 1 Attorney Jan.11,1 949. Y -J. c. NLOR RECIPROCATING PUMP OR AMOTOR I l 3Sheets-Sheet 2 File'd Jan. `4. 1945 Jan. 11,1949. J, Q NAYLOR 2,458,869I RECIPROCATING PUMP 0R MOTOR l Filed Jan. 4, 1945 3 Sheets-Sheet 5Attorney Patented Jan. 11, 1949 Joshua Challner Naylor, Monkseaton,England,

assignor to `Vickers-Armstrongs Limited, Lon- 1 don, England, a companyof Great Britain "Application January 4, 1945, Serial No. 571,249

` In Great Britain October 27, 1943 f; section 1, Public Law 690, Augusts, 1946 Patent expires October 27, 1963 This invention relates4 toreciprocating pumps or motors of the iixed or variable stroke radialtype in which cylinders are disposed in a housing about a shaft carryingAan eccentric, the pistons reciprocating in the cylinders and being indriving connection with the eccentric. For example the invention isconcerned with pumps which include a series of radially arrangedcylinders each containing an associated piston, thel flow of fluid toand from the cylindersbeing controlled by a suitable valve or valves forexample, the eccentrically operated valve of the self-sealing typeforming the subject of prior BritishPatent No. 503,148. Examples of suchradial pumpsare described and illustrated.' in the Vspecifications anddrawings accompanying co-pending patent applications Nos. 505,491 and505,490, b'othled October 8,

1943, the latter having issued as Patent No.'

2,426,100 on August 19, 1947.

It has been proposed in the case of radial pumps which are eccentricallyoperated to t the eccentric with a surrounding annular ring, said ringbeing freely revoluble about the eccentric and to bifurcate or nat theinner end of each piston for the reception of a roller' or rollers, thelatter making rolling contact with said ring, each roller being mountedupon a pinwhich extends transversely through aligned borings in thepistons, all the rollers being maintained in contact with the ringduring the suction or return stroke of the pistons by a retaining ringor rings disposed alongside the pistons, said retaining rings or ringssurrounding the pins or rollers and contacting their outer'peripheralsurfaces. It is desirable in such pumps that any tendency for thepistons to rotate about their axes during operation should be preventedand the chief object of the present invention is to obvia-te any suchaxial turning movement. l

According to this invention a radial pump or motor of the type employing4an eccentric to drive the piston is characterised Aby the combinationwith the pistons and the eccentric of means to prevent rotation of thepistons about their axes, said means comprising two endless abutmentscommon to all of the pistons and engaging with co-operatingabutmentscarried bythe pistons. One form of the invention comprisesannular retaining rings which engage flats on the pistons, another formcomprises a channel in the periphery of the eccentricreceiving rollerson the pistons, and a still further form consists in engaging grooves inthe piston pins with the inner edges of two retaining rings.

In order that the invention may be clearlyv Claims.

understood and readily carried into eect drawings are appended heretoillustrating embodiments thereof, and wherein,k

Figure 1 is a fragmentary sectional view taken diametrically through oneof a set of pistons in lradial cylinders and showing the co-operation ofretaining rings and flats on the piston for preventing rotation of thepiston about its axis.

Figure 2 is a sectional side elevation through the appropriate part ofthe pump or motor to show the piston rotation preventing means of Figure1.

Figure 3 is a broken diametrical sectional elevation through a pumpincorporating retaining rings which engage in notches in the end` partsof the piston pins projecting beyond the piston for preventing rotationof the pistonsabout their axes.

Figure 4 is a section on the line la-4a of Figure 3 but showing the.pistons in full.

Figure 5 is a section similar to Figure 3 but showing an alternativemanner of effecting interengagement between the piston pins and the reytaining rings.

Figure 6 is a detail sectional elevation showing the use. of a channelin the eccentric and adapted to co-operate with rollers on the pistonsto prel vent the said rotation of the pistons.

I invention.

Referring to Figures 1 and 2 of the drawings,

, each piston I has a bifurcated inner end in the form of twosymmetrical parallel limbs 2 having nat inner and outer faces parallelwith a diameter f of the piston and sufliciently widely spaced to mentas far as the present invention is concerned ,y

receive a thick cylindrical roller 3 contacting the outer ring' 4 of theeccentric 5 mounted on the pumpshaft 6. Each roller has nat annular sidefaces making light Contact with the inner flat faces of lthe furcations2 and is supported by a cylindrical piston pin 'l passed throughcircular holes in the furcations and lightly contacting at their endswith two retaining rings 8 of L section which engage by the inner tracksof vtheir outer cylindrical parts with the pins 'l to maintain therollers in Contact with the ring 4 during the suction or return strokeof the piston. This ring 4 is supported on the eccentric by needlebearings 9.

The chief features ofthe foregoing arrangel is that the opposed annularfaces l0 of the 3 tact with the outer fiat faces oi the furcations 2whilst the outer annular faces il make sliding Contact with fixedannular guide plates i2. It will beappreciated that with suchanyarrangement 'that the retaining ringsform positive abutmentspreventing rotation of the pistons about their axes.

In the embodiment shown in Figures 3 and 4 and thereby maintain the-largest areaofannular face iof eachsuch ring `incontact withtheappropriate flat iurcationZ, so thataxialturn- -ing movement of theApistons Vis prevented* and furthermore theretaining ringsby virtue oftheir Anotched engagement with the pins "2 serve Ato prevent endwisemovement of `the ypins within their ,-borings in the piston and soconstitute a self retaining assembly. The pins'support Vrollers 3 theannular faces of which rotate against the opposed nat-faces of the`furcations 2 of theinner ends of the pistons.

Itis-preferred `that with the above arrangement eachretaining ringshallbe of substantially L shape in cross-sectionas shown; each retainingring being so'disposed that the `inner vfacefof the inwardly directedwebthereof makes light rubloing contact with the adjacent face of thepiston, theother lor axially directed web being `directed outwardlmj.e.' away from the piston and acting as a' stifijening web forthering. i

In the alternative arrangement shown inFigure5` each pin'l is cut awayat each'endto form a step l5 on the outer vpart of itsperipheralsurface; as distinct from being notched in such outer part 'asaforesaid,k to form tworportions which proj ect from the piston; andare` reduced in thickness, the outer faces ofthe projecting "ends of thepin being-orarcuate .shaper and ofi a curvature corresponding to thejinner peripheral curvavture of the retaining ringsV 8.

The retaining Vrings in this modiedarraneementA maybe of simpleArectangularl shape in crosssection as shown,A the inner 'faces of theretainling 'rings 'making lightV rubbing Acontact with the adjacentatsides of the forked winner end of the appropriate piston as hithertoand the outer faces with suitable 'abutments i2 in/the pump casing. ByVcutting away the extremities of the pins to a suiicient depth, .theoverall diameters of `the retaining rings areV consequently 4reduced,thus reducing to a certain extent the overall diameter yof the pump.

In eitherof the arrangements hereinbefore described the rollers may makesimpleY surface contact with Athefring4 which is freejrevolubly mountedupon the e ccen tricj5,.but in an alternative arrangement (see Figure 6)the'ringiIVmay be formedwith continuous peripheral recess YI6constituting a guideway'in which the rollers'jcan run. This Aguidewayreceives the rollersj for a depth adequate forv preventing thepistons'turn- 'ing about theiraxes andrelieving the retaining lthe inneredges of the retaining rings. '7 is shown an arrangement affording thisspin I as `wellv asaffording the minimum friction between veach,roller-f3 andfpiston pin 1. isghollowed-ytotsfit smoothly upon acylindrical tion of the axes of the pistons relatively to the peripheryof the eccentric it is desirable with some pumps and motors that thepiston pins i should'be freeto spin abouttheir axes rather .thanto.-restrairrsuch'l spinning by the use of the steps l5 radiused toconform with the radius of In Figure The piston pin l centre pinw'l-'l.which projects beyond the ends of -the piston pin l and the outer flatsof the furcationsjj toirnakerolling contact with the inner cylindricalsurfaces of the opposed axially proieotingpartsf the retaining rings 8whi-ch by A -their'oppo'sed annular faces I8 locate the pinAL1.fagainsi; axial displacement whilst having a clearance I'S betweentheir opposed annular Vedges and the -outer"flats of the furcations 2.

vented, tl'i e' s a .rne manner as `inf-Figure l6, i. e.

' b yfthe roller j3 running Ain' a circumferential channel 1 6 `in theeccentric ring 4.

' Instead ofiabifurcatedjinner endto each piston a single central ordiametric'al luglv i2 0` canwbe provided as shownjinjFigureiS,the pistonpin 'I carrying a pair `of rollers running `in"tvv o circumferentialchannels-i5 (orasingle wide channel) in the eccentr iinggl 'toA preventrotation of fthe piston' ,aboutv 'its` axis. -'herollers 3 can .engageand'.,traversethe.inner'tracks of the two retaining rines `willCllllaretheir axially directed A,cylindricalgjperipl'ieries vinterposed betweenthe Tellerstand thesteps .zliolmd in the' peripheries of thepistonsjwhen millingpthe lwugsf-Z.

The use of ,thepins 'l l,, orof theypairs of rollers a, engagingthe'inner'ftraclrs 'Aof the retaining -rings as shown Yin Figures''7"and8 considerably free -t0..pr,eeSS withal@ imposing idrae On theminimises 'friction and'leaves' v"the retaining rings pistonl pinsvindirections' transverse to the`A piston ,axesaand'ikeeps .theaxss f thepiston `rms I ,truly Sguared in'relatento the uplane parallel WitheH'fthe piston axes ltrwill',beapnre'ciated 4that 'the retaining ringswheretheyiengage thev flats on the pistons or the Vgijoovesjinitl'iepistonjpins,V andthe channels it? where they .engage the "flats orannular Aif aces of "therollersjconstitute V`twoendless annularabutjrnents engaging with co-operating abutments carri ed jbyf'thepistons? to prevent rotation of -the 'pistons about their-axes.

lclamr f .142111 agpumpgfmbwrif the radial' type allv'lirigiersjsubstantially vradiating from the periphery oftheeccjer'itricA and ymeans' restraining-` thepistons from Aturningabout their axes; 's ai d means comprising*diametrically opposed ilatson the pistons ian'd'jagpair o faxially spaced annular retaining ringsengaging the A-fla'ts on the pistonsyhea'dless cylindricalv piston pinspassed .diametrically through the` pistons and 'storming axles 4for rtherollers,`and integral abutmentsur- 'fa-ces on' the 4v pist/on: "pinsengaging the )retaining v'rings' at "annularsurfaces opposed to the-piston Aforholding thejpistonjpnsagainst' axial displacethe peripheryofthe'eccentric-"and'means restraining the pistons fromr turning abouttheir axes, said means comprising diametrically opposed flats on thepistons and a pair of axiallyv spaced annular retaining rings engagingthe flats on the pistons, headless cylindrical piston pins passed,4

diametrically through the pistons and forming axles for the rollers, andintegral abutment surfaces on the piston pins engaging the retainingrings at annular surfaces opposed to the piston for holding the pistonpins against axial displacement, said abutment surfaces on the pistonpins comprising plane ends perpendicular to the axes of the piston pinsabutting against opposed annular surfaces of the retaining rings,opposed inwardly directed peripheral flanges integral with saidretaining rings abutting against said flats on the piston.

3. In a pump or motor of the radial type an eccentric, cylinder,cylinders substantially radiating from the eccentric, pistonsreciprocating in the cylinders, rollers carried by the pistons andengaging the periphery of the eccentric and means restraining thepistons from turning about their axes, said means comprisingdiametrically opposed flats on the pistons and a pair of axially spacedannular retaining rings engaging the flats on the pistons, headlesscylindrical piston pins passed diametrically through the pistons andforming axles for the rollers, and integral abutment surfaces on thepiston pins engaging the retaining rings at annular surfaces opposed tothe pistons for holding the piston pins against axial displacement, saidabutment surfaces on the piston pins comprising steps formed in the endsof the piston pins and offering to the opposed surfaces of the retainingrings plane surfaces co-planar with the llats on the pistons.

4. In a pump or motor of the radial type an eccentric, cylinderssubstantially radiating from the eccentric, pistons reciprocating in thecylinders, rollers carried by the pistons and engaging the periphery ofthe eccentric and means restraining the pistons from turning about theiraxes, said means comprising diametrically opposed ats on the pistons anda pair of axially spaced annular retaining rings engaging the flats onthe pistons, headless cylindrical piston pins passed diametricallythrough the pistons and forming axles for the rollers, and integralabutment surfaces on the piston pins engaging the retaining rings atannular surfaces opposed to the piston for holding the piston pinsagainst axial displacement, said abutment surfaces comprising grooves inthe peripheries of the pins formed between their ends and the flats onthe pistons and engaged by the retaining rings.

5. In a. radial pump or motor a set of radial cylinders, pistonsreciprocating in said cylinders, an eccentric, rollers carried by thepistons and tracking against the periphery of the eccentric, a pair ofdiametrically opposed ats on each piston, two axially spaced annularretaining rings contacting with all of said flats, forked ends with saidpistons between the furcations of which are located the said rollers,said flats comprising the outer surfaces of the furcations, headlesspiston pins passing through said furcations and comprising the axles ofthe rollers, opposed inwardly directed cylindrical flanges with saidrings engaging by their free ends against said ats and overhanging theends of the piston pins, and plane surfaces on the ends of the pistonpins perpendicular to the axes of the pins and engaging opposed -annularsurfaces of the retaining rings.

6. In a radial pump or motor a set of radial cylinders, pistonsreciprocating in said cylinders,

an eccentric, rollers carried by the pistons and tracking against theperiphery of the eccentric, a pair of diametrically opposed ats on eachpiston, two axially spaced annular retaining rings 'contacting with allof said iiats, forked ends with said pistons between the furcations ofwhich are located the said rollers, said flats comprising the outersurfaces of the furcations, headless piston pins passing through saidfurcations and comprising the axles of the rollers, steps formed at theends of the piston pins by removing parts of the peripheries of suchpins and engaging by their axially directed surfaces with internalcylindrical surfaces of the retaining rings, said axially directedsurfaces of the pins being radiused to correspond with the radius ofsuch internal surface of the retaining rings, and the inner ends of suchsteps being co-planar With and abutting against the opposed annularsurfaces of the retaining rings.

7. In a radial pump or motor an eccentric, a set of cylinders disposedcircumambiently about the eccentric, pistons reciprocating in thecylinders, forks on the ends of the pistons opposed to the eccentric,piston pins passing through such forked ends, rollers in such forkedends rotating on the pins, an endless channel in the periphery of theeccentric in which the rollers track, the opposed annular side walls ofthe channel engaging the sides of the rollers to prevent rotation of thepistons about their axes, and a pair of retaining rings surrounding andcontacting the ends of the piston pins.

8. In a radial pump or motor an eccentric, a set of cylinders disposedcircumambiently about the eccentric, pistons reciprocating in thecylinders, forks on the ends of the pistons opposed to the eccentric,piston pins passing through such forked ends, rollers in such forkedends rotating on the pins, an endless channel in the yperiphery of theeccentric in which the rollers track, the opposed annular side walls lofthe channel engaging the sides of the rollers to prevent rotation of thepistons about their axes, each piston pin being constituted by a hollowcylindrical outer member fixed in the piston and a centre pin free torotate in said hollow member and engaged at its ends with retainingrings.

9. In a radial pump or motor an eccentric, a set of cylinders disposedcircumambiently about the eccentric, and pistons reciprocating in thecylinders, rollers carried by the ends of the pistons opposed to theeccentric, an endl-ess channel in the periphery of the eccentric inwhich the rollers track, the opposed annular side walls of the channelengaging the sides of the rollers to prevent rotation of the pistonsabout their axes, piston pins passed diametrically through the pistonsand forming the axles of the rollers, and a pair or retaining rings, theends of the piston pins having parts of their peripheries removed toform steps seating in the retaining rings.

10. In a radial pump or motor an eccentric, a set of cylinders disposedcircumambiently about the eccentric, and pistons reciprocating in thecylinders, a pair of co-axial rollers carried by the end of each pistonopposed to the eccentric, and endless channelling in the periphery ofthe eccentric in which the pairs of rollers track, opposed annular sideWalls of the channelling forming abutments for sides of the rollers toprevent rotation of the pistons about their axes7 piston pins passeddiametrically through the pistons and each forming the axle for a pairof rollers carried ausgew ,7 18 by .lanpistorr and apairofsretainngringsmith VREFERENCES-,CITED opposed :inwardly directed peripheral:parts 1 over- ;hanging A`the .peripheriesvof :the :rollemandthe:@Thedfollowng#references vare 0f record in the ncircumferences ofthepistons -each beng out 'eLOfhS-patllti away `to a Ylugformationatvtheiinner-end-toJ-acv 5 UNITED :STATES PATENTS Comm'odatethe rollers and the saidfinwardly v directed perplleralpartsy ofthe-retaining rings. "Number 'Name Date JOSEUA CHAI'JNERNAYLQR1.-,0233635 Ruwell Apr. 16, 1912 ...new

